1,115 research outputs found

    Aging and scaling laws in β\beta-hydroquinone-clathrate

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    The dielectric permittivity of the orientational glass methanol(x=0.73)-β\beta-hydroquinone-clathrate has been studied as function of temperature and waiting time using different temperature-time-protocols. We study aging, rejuvenation and memory effects in the glassy phase and discuss similarities and differences to aging in spin-glasses. We argue that the diluted methanol-clathrate, although conceptually close to its magnetic pendants, takes an intermediate character between a true spin-glass and a pure random field system

    Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame

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    Introduction: The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fi xators for all these tibial fractures has been shown to be crucial. Methods: A fi ve-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure. Results: A total of 112 patients (85 Ilizarov, 37 TSF) were identifi ed for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no signifi cant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no signifi cant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman's r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group. Conclusions: Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a signifi cant role in complex tibial fractures

    Aging and memory effects in beta-hydrochinone-clathrate

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    The out-of-equilibrium low-frequency complex susceptibility of the orientational glass methanol(73%)-beta-hydrochinone-clathrate is studied using temperature-stop protocols in aging experiments . Although the material does not have a sharp glass transition aging effects including rejuvenation and memory are found at low temperatures. However, they turn out to be much weaker, however, than in conventional magnetic spin glasses.Comment: 5 pages RevTeX, 6 eps-figures include

    Theory of Scanning Tunneling Spectroscopy of a Magnetic Adatom on a Metallic Surface

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    A comprehensive theory is presented for the voltage, temperature, and spatial dependence of the tunneling current between a scanning tunneling microscope (STM) tip and a metallic surface with an individual magnetic adatom. Modeling the adatom by a nondegenerate Anderson impurity, a general expression is derived for a weak tunneling current in terms of the dressed impurity Green function, the impurity-free surface Green function, and the tunneling matrix elements. This generalizes Fano's analysis to the interacting case. The differential-conductance lineshapes seen in recent STM experiments with the tip directly over the magnetic adatom are reproduced within our model, as is the rapid decay, \sim 10\AA, of the low-bias structure as one moves the tip away from the adatom. With our simple model for the electronic structure of the surface, there is no dip in the differential conductance at approximately one lattice spacing from the magnetic adatom, but rather we see a resonant enhancement. The formalism for tunneling into small clusters of magnetic adatoms is developed.Comment: 12 pages, 9 figures; to appear in Phys. Rev.

    The acquisition of Sign Language: The impact of phonetic complexity on phonology

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    Research into the effect of phonetic complexity on phonological acquisition has a long history in spoken languages. This paper considers the effect of phonetics on phonological development in a signed language. We report on an experiment in which nonword-repetition methodology was adapted so as to examine in a systematic way how phonetic complexity in two phonological parameters of signed languages — handshape and movement — affects the perception and articulation of signs. Ninety-one Deaf children aged 3–11 acquiring British Sign Language (BSL) and 46 hearing nonsigners aged 6–11 repeated a set of 40 nonsense signs. For Deaf children, repetition accuracy improved with age, correlated with wider BSL abilities, and was lowest for signs that were phonetically complex. Repetition accuracy was correlated with fine motor skills for the youngest children. Despite their lower repetition accuracy, the hearing group were similarly affected by phonetic complexity, suggesting that common visual and motoric factors are at play when processing linguistic information in the visuo-gestural modality

    Encouraging Human Papillomavirus Vaccine Uptake: A Healthcare Improvement Project

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    Abstract Problem: Human papillomaviruses are the causative agents of \u3e95% of cervical cancers, most oropharyngeal and anogenital cancers, yet the vaccination status of the population remains critically low despite Gardasil9 offering robust protection against HPV-related disease. Methods: This quality improvement project utilized a descriptive, observational design to assess the effect of the HPV Encouragement Bundle, a two-step intervention to improve HPV vaccine uptake. Quantitative data was collected via retrospective chart review to assess the effect of the intervention on first-dose administration of Gardasil9 (series initiation), as well as overall Gardasil9 vaccine uptake. Results: Following implementation, Gardasil9 first dose uptake increased from 0% to 8.45%, and overall Gardasil9 uptake increased from 0.8% to 12.68%, in pre- and post-intervention groups, respectively. A Chi-square test of independence was performed to examine the relationship between intervention groups and Gardasil9 administration. A statistically significant relationship was established between intervention groups and Gardasil9 administration, with alpha value of .05, χ2(1) = 14.19, p \u3c .001. Persons in the post-intervention group were more likely to be administered a dose of Gardasil9. Implications for practice: Widespread use of the HPV Encouragement Bundle is a cost-effective, inclusive intervention that could be used to improve Gardasil9 vaccine uptake

    Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags

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    Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means

    Bombesin and bombesin antagonists: studies in Swiss 3T3 cells and human small cell lung cancer.

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    Bombesins are potent growth factors for murine Swiss 3T3 cells. Using these cells in chemically defined conditions we have been able to characterise the bombesin receptor and the early signals preceding DNA synthesis. We describe two substance P analogues [DArg1, DPro2, DTrp7,9, Leu11] substance P and [DArg1, DPhe5, DTrp7,9, Leu11] substance P which competitively block the binding of bombesins to their receptor and all the events leading to mitogenesis. Bombesins are secreted by human small cell lung cancers (SCLC) and may act as autocrine growth factors for these tumours, so the development of peptide bombesin antagonists could have therapeutic implications. We demonstrate that the antagonists can reversibly inhibit the growth of SCLC in vitro, with relatively little effect on other lung tumours
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